body {
    width: 100%;
    height: auto;
    margin: 0;
    padding: 0;
}
.mainBody{
    width: 100%;
    height: 100%;
}
#pano{
    position: absolute;
    height: 100%;
    width: 100%;
    z-index: -1;
}

.sign{
    position: relative;
    width: 30%;
    height: 30em;
    background-color: rgb(255, 255, 255,.5);
    margin: 0 auto;
    top: 10em;
    border-radius: 0.3em;
}
.sign_title{
    width: 100%;
    height: 20%;
    text-align: center;
}
.sign_title>span{
    position: relative;
    top: 1em;
    font-size: 3em;
    font-weight: bold;
    color: rgb(0, 0, 0,0.5);
}
.sign_user{
    width: 100%;
    height: 80%;
    text-align: center;
}
form{
    position: relative;
    top: 3em;
}






